Gas additives --Help??? Other fuel questions

[retired chem teacher]

I know this probably has been on here lots of times and I have missed it.  But with all the ethanol fuel out there what are you using to combat the problems???  I always try to find ethanol free high octane fuels but that is hard to do in a lot of areas. Plus who know if they are really ethanol free?? Also lots of ideas about storing with with tank full of fuel vs part full??  What about running outboard out of fuel with fuel line detached for extended periods??  All help appreciated

[Dutch]

I have a Merc.  I use 2 additives Quickare and Quickleen along with 91 ethanol free.  That is what was recommended by my comes by Merc technician.  My last Merc was still going strong after 14 years and lots of hours and my current one is starting year 8.

[aarchdale@coresleep.com]

My theory has been to use all that gas i put in for the day and never let it set more than two weeks. All those additives are just a money grab for the most part. Depending on your engine lots are not meant to run on 91. I had an Opti and always ran 87 no problem just dont let it sit.  I used all the treatments for a bit and then quit and nothing has changed except i have more money

[tjm]

1 hour ago, retired chem teacher said:

Plus who know if they are really ethanol free??

Shake a couple ounces up with some water, then let settle; the alcohol will mix with the water making it look like an increased volume of water and a decreased volume of gas, takes maybe 5 minutes with any clear container.

1 hour ago, retired chem teacher said:

to combat the problems??

I'm not a boat guy, but what are the problems with ethanol blends that you are trying to combat?  It's a pretty good solvent and most gas additives are just solvents. 

 

[fishinwrench]

All engines of all kinds have been designed to run efficiently on 87% octane fuel since 1996, and since the main concern boaters should have with alcohol enhanced fuel is its shelf life there is absolutely no benefit to higher octane fuel..... because it is LESS fresh at the time of purchase, in all circumstances.    

Regardless of manufacturer claims there is no true benefits to ANY fuel additive.   Even the engine maker branded crap.

The best fuel for your outboard is the freshest 87% fuel you can find....with NO additional additives of any kind.    And when it gets old.....kill weeds with it.  

 

[Ketchup]

10 hours ago, fishinwrench said:

All engines of all kinds have been designed to run efficiently on 87% octane fuel since 1996, and since the main concern boaters should have with alcohol enhanced fuel is its shelf life there is absolutely no benefit to higher octane fuel..... because it is LESS fresh at the time of purchase, in all circumstances.    

Regardless of manufacturer claims there is no true benefits to ANY fuel additive.   Even the engine maker branded crap.

The best fuel for your outboard is the freshest 87% fuel you can find....with NO additional additives of any kind.    And when it gets old.....kill weeds with it.  

 

Tho true for most engines, compression can play a part in that.  A Yamaha VMax 150 will run fine on 87, but you will see a slight performance decrease with that same fuel in a 250.  Flash that 250 and run 87 and you aren’t helping yourself.  That’s where the 91 comes in.  I’ve ran 87, 89, and the recommended 91 in my flashed 250 and no comparison between 87 and 91 in it.  

[MrGiggles]

If you premix, most mix oils already have stabilizers in them.

JMO but no stabilizer on the market is better than fresh gas. Use it up. Half full or full makes little difference, let it sit for years and you will have problems either way.

[fishinwrench]

2 hours ago, Ketchup said:

but you will see a slight performance decrease with that same fuel in a 250.

If you do then that computer isn't doing what it is allegedly designed to do.   

[tjm]

back when I used read  the labels, and  SDS sheets, every fuel additive that I studied was either kerosene, white gas, lacquer thinner or a mix of those.    And the water removers were all alcohol. Of course they used different names for the stuff, like 'petroleum distillate', 'naphtha', 'ethanol' and so on.

I'm not a fan of ethanol as fuel, it has about 2/3 as much 'power' as gasoline, and when mixed with gasoline won't stay mixed, but the modern  engines are designed for it and don't need any thing else. Then too,  whatever they are using to make the non-ethanol fuel these days neither looks nor smells like gas and it doesn't stay  mixed either. I need to get rid of the 5gal cans and only buy gas one day at a time in gallon cans so when I dump the leftovers it's not such a loss. 

[Ketchup]

30 minutes ago, fishinwrench said:

If you do then that computer isn't doing what it is allegedly designed to do.   

Possibly, but the recommended octane ratings differ, as should be. Same with automotive engines, RC engines, etc. so a 250 should technically run poorer with 87 vs 89 vs 91 vs 93.  
 

Picture one of those go fast, 200 mph LoZ boats running on 87, or an NHRA funny car running on 89.